1. Field of the Invention
The present invention relates to an LCD (Liquid Crystal Display) apparatus, and more particularly to an LCD apparatus having an enhanced response speed and light transmittance.
2. Description of the Related Art
An LCD apparatus, generally, includes a TFT (Thin Film Transistor) substrate on which a TFT for switching a pixel is formed, a color filter substrate on which a common electrode is formed and liquid crystal interposed between the TFT substrate and color filter substrate. The LCD apparatus applies a voltage to a pixel electrode and the common electrode formed at the TFT substrate and color filter substrate, respectively, so as to drive the liquid crystal and to control a light transmittance of the liquid crystal, thereby displaying an image.
In recent, an LCD apparatus is widely used, and thus consumer's demand for improvements is strong, for example, visual properties, display qualities, etc., of the LCD apparatus. In order to meet consumer's demand, an LCD apparatus having a vertically aligned mode (hereinafter, referred to as “VA mode”) has been developed.
The VA mode LCD apparatus includes two substrates treated by a vertically aligned treatment and liquid crystal interposed between the two substrates and having a negative type dielectric constant anisotropy.
The liquid crystal assumes a homeotropic alignment, and thus the liquid crystal is aligned in a direction substantially perpendicular to surfaces of the two substrates when a voltage is not applied to the two substrates, thereby maintaining the liquid crystal in a black mode state. On the contrary, the liquid crystal is aligned in a direction substantially parallel to the surfaces of the two substrates when the voltage is applied to the two substrates, thereby displaying the maintenance of the liquid crystal in a white mode state. When a voltage, which is smaller than the voltage applied to the two substrates, is applied to the two substrates while the liquid crystal is aligned in the direction substantially parallel to the surfaces of the two substrates, the liquid crystal is aligned in a direction inclined with respect to the surfaces of the two substrates.
FIG. 1 is a schematic plane view showing a conventional PVA mode LCD apparatus. FIG. 2 is a cross-sectional view taken along the line B-B′ for showing the conventional PVA mode LCD apparatus shown in FIG. 1.
Referring to FIGS. 1 and 2, a conventional PVA mode LCD apparatus includes a first substrate 100 on which a TFT 110 is formed, a second substrate 200 on which a light-shielding layer 210 is formed, and liquid crystal (not shown) interposed between the first and second substrates 100 and 200. A polarizing film (not shown) is disposed under the first substrate 100 and on the second substrate 200 so as to selectively transmit a light provided from a backlight assembly (not shown) according to a polarizing axis thereof.
The first substrate 100 includes a plurality of gate lines 120 substantially parallel to each other, a plurality of data lines 130 substantially parallel to each other and substantially perpendicular to the gate lines 120, a pixel area defined by the gate and data lines 120 and 130 and a pixel electrode 140 formed on the pixel area. The second substrate 200 includes a common electrode 220 formed on the light-shielding layer 210.
An LCD apparatus, generally, includes first, second and third electrodes 150, 160 and 170 so as to align the liquid crystal in a multi-domain structure or in a different direction from each other. The first electrode 150 is formed on the first substrate 100 and the second and third electrodes 160 and 170 are formed on the second substrate 200.
The first electrode 150 includes a first protruding portion 150a symmetrically formed to each other with respect to an imaginary line A-A′ and inclined with respect to the data line 130 and a second protruding portion 150b substantially parallel to the data line 130 so as to connect ends of the first protruding portion 150a. 
The second protruding portion 150b is completely covered by the light-shielding layer 210 formed on the second substrate 200. That is, the light-shielding layer 210 has a width of about 28 micrometers wider than a sum of a width of the second protruding portion 150b formed at both sides of the data line 130. The first electrode 150 is insulated from the pixel electrode 140 by means of a gate-insulating layer 102 and the second protruding portion 150b is spaced apart from the data line 130 by an interval of about 5.5 micrometers.
The second electrode 160 has a V-shape and the first and second electrode 150 and 160 are alternately arranged with one another. The third electrode 170 is inwardly disposed between the second electrode 160 and an adjacent second electrode and has a Y-shape. The second and third electrodes 160 and 170 are formed by partially removing the common electrode 220 formed on the second substrate 200.
FIG. 3A is a schematic plane view showing a tilting direction of liquid crystal at an area adjacent to a data line of a conventional LCD apparatus. FIG. 3B is a schematic plane view showing a polarizing axis and a tilting direction of liquid crystal at an area adjacent to a data line of a conventional LCD apparatus.
As shown in FIG. 3A, the pixel electrode 140 is overlapped with the second protruding portion 150b adjacent to the data line 130 so as to completely cover the second protruding portion 150b. 
In general, the liquid crystal having the negative type dielectric constant anisotropy is tilted in an angle of about 45 degrees with respect to a polarizing axis. However, the liquid crystal adjacent to an end of the pixel electrode 140 is vertically aligned while an electric field is not applied thereto, so that the liquid crystal is maintained in the black mode state 300.
Referring to FIG. 3B, the liquid crystal adjacent to the end of the pixel electrode 140 is tilted in a same direction as the polarizing axis 310 at an initial stage to which the electric field is applied, and then the liquid crystal adjacent to the end of the pixel electrode 140 is tilted in the angle of about 45 degrees with respect to the polarizing axis 310 due to the liquid crystal not adjacent to the end of the pixel electrode 140.
That is, since the liquid crystal adjacent to the end of the pixel electrode 140 is tilted in the same direction as the polarizing axis 310 even if the electric field is applied to the liquid crystal, brightness of the LCD apparatus may be deteriorated.
Also, in order to tilt the liquid crystal adjacent to the end of the pixel electrode 140 in the angle of about 45 degrees with respect to the polarizing axis 310, two step-motion, for example, such as arranging in the same direction as the polarizing axis 310 and tilting in the angle of about 45 degrees with respect to the polarizing axis 310, has to be performed. Thus, tilting processes of the liquid crystal adjacent to the end of the pixel electrode 140 may become complex.